i2o_scsi.c

h内核

			switch (as) {
			case 0x0E:
				/* SCSI Reset */
				cmd->result = DID_RESET << 16;
				break;

			case 0x0F:
				cmd->result = DID_PARITY << 16;
				break;

			default:
				cmd->result = DID_ERROR << 16;
				break;
			}

			break;
		}

		cmd->scsi_done(cmd);
		return 1;
	}

	cmd->result = DID_OK << 16 | ds;

	cmd->scsi_done(cmd);

	dev = &c->pdev->dev;
	if (cmd->use_sg)
		dma_unmap_sg(dev, (struct scatterlist *)cmd->buffer,
			     cmd->use_sg, cmd->sc_data_direction);
	else if (cmd->request_bufflen)
		dma_unmap_single(dev, (dma_addr_t) ((long)cmd->SCp.ptr),
				 cmd->request_bufflen, cmd->sc_data_direction);

	return 1;
};

/**
 *	i2o_scsi_notify_controller_add - Retrieve notifications of added
 *					 controllers
 *	@c: the controller which was added
 *
 *	If a I2O controller is added, we catch the notification to add a
 *	corresponding Scsi_Host.
 */
static void i2o_scsi_notify_controller_add(struct i2o_controller *c)
{
	struct i2o_scsi_host *i2o_shost;
	int rc;

	i2o_shost = i2o_scsi_host_alloc(c);
	if (IS_ERR(i2o_shost)) {
		osm_err("Could not initialize SCSI host\n");
		return;
	}

	rc = scsi_add_host(i2o_shost->scsi_host, &c->device);
	if (rc) {
		osm_err("Could not add SCSI host\n");
		scsi_host_put(i2o_shost->scsi_host);
		return;
	}

	c->driver_data[i2o_scsi_driver.context] = i2o_shost;

	osm_debug("new I2O SCSI host added\n");
};

/**
 *	i2o_scsi_notify_controller_remove - Retrieve notifications of removed
 *					    controllers
 *	@c: the controller which was removed
 *
 *	If a I2O controller is removed, we catch the notification to remove the
 *	corresponding Scsi_Host.
 */
static void i2o_scsi_notify_controller_remove(struct i2o_controller *c)
{
	struct i2o_scsi_host *i2o_shost;
	i2o_shost = i2o_scsi_get_host(c);
	if (!i2o_shost)
		return;

	c->driver_data[i2o_scsi_driver.context] = NULL;

	scsi_remove_host(i2o_shost->scsi_host);
	scsi_host_put(i2o_shost->scsi_host);
	pr_info("I2O SCSI host removed\n");
};

/* SCSI OSM driver struct */
static struct i2o_driver i2o_scsi_driver = {
	.name = OSM_NAME,
	.reply = i2o_scsi_reply,
	.classes = i2o_scsi_class_id,
	.notify_controller_add = i2o_scsi_notify_controller_add,
	.notify_controller_remove = i2o_scsi_notify_controller_remove,
	.driver = {
		   .probe = i2o_scsi_probe,
		   .remove = i2o_scsi_remove,
		   },
};

/**
 *	i2o_scsi_queuecommand - queue a SCSI command
 *	@SCpnt: scsi command pointer
 *	@done: callback for completion
 *
 *	Issue a scsi command asynchronously. Return 0 on success or 1 if
 *	we hit an error (normally message queue congestion). The only
 *	minor complication here is that I2O deals with the device addressing
 *	so we have to map the bus/dev/lun back to an I2O handle as well
 *	as faking absent devices ourself.
 *
 *	Locks: takes the controller lock on error path only
 */

static int i2o_scsi_queuecommand(struct scsi_cmnd *SCpnt,
				 void (*done) (struct scsi_cmnd *))
{
	struct i2o_controller *c;
	struct Scsi_Host *host;
	struct i2o_device *i2o_dev;
	struct device *dev;
	int tid;
	struct i2o_message __iomem *msg;
	u32 m;
	u32 scsi_flags, sg_flags;
	u32 __iomem *mptr;
	u32 __iomem *lenptr;
	u32 len, reqlen;
	int i;

	/*
	 *      Do the incoming paperwork
	 */

	i2o_dev = SCpnt->device->hostdata;
	host = SCpnt->device->host;
	c = i2o_dev->iop;
	dev = &c->pdev->dev;

	SCpnt->scsi_done = done;

	if (unlikely(!i2o_dev)) {
		osm_warn("no I2O device in request\n");
		SCpnt->result = DID_NO_CONNECT << 16;
		done(SCpnt);
		return 0;
	}

	tid = i2o_dev->lct_data.tid;

	osm_debug("qcmd: Tid = %03x\n", tid);
	osm_debug("Real scsi messages.\n");

	/*
	 *      Obtain an I2O message. If there are none free then
	 *      throw it back to the scsi layer
	 */

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return SCSI_MLQUEUE_HOST_BUSY;

	/*
	 *      Put together a scsi execscb message
	 */

	len = SCpnt->request_bufflen;

	switch (SCpnt->sc_data_direction) {
	case PCI_DMA_NONE:
		scsi_flags = 0x00000000;	// DATA NO XFER
		sg_flags = 0x00000000;
		break;

	case PCI_DMA_TODEVICE:
		scsi_flags = 0x80000000;	// DATA OUT (iop-->dev)
		sg_flags = 0x14000000;
		break;

	case PCI_DMA_FROMDEVICE:
		scsi_flags = 0x40000000;	// DATA IN  (iop<--dev)
		sg_flags = 0x10000000;
		break;

	default:
		/* Unknown - kill the command */
		SCpnt->result = DID_NO_CONNECT << 16;
		done(SCpnt);
		return 0;
	}

	writel(I2O_CMD_SCSI_EXEC << 24 | HOST_TID << 12 | tid, &msg->u.head[1]);
	writel(i2o_scsi_driver.context, &msg->u.s.icntxt);

	/* We want the SCSI control block back */
	writel(i2o_cntxt_list_add(c, SCpnt), &msg->u.s.tcntxt);

	/* LSI_920_PCI_QUIRK
	 *
	 *      Intermittant observations of msg frame word data corruption
	 *      observed on msg[4] after:
	 *        WRITE, READ-MODIFY-WRITE
	 *      operations.  19990606 -sralston
	 *
	 *      (Hence we build this word via tag. Its good practice anyway
	 *       we don't want fetches over PCI needlessly)
	 */

	/* Attach tags to the devices */
	/*
	   if(SCpnt->device->tagged_supported) {
	   if(SCpnt->tag == HEAD_OF_QUEUE_TAG)
	   scsi_flags |= 0x01000000;
	   else if(SCpnt->tag == ORDERED_QUEUE_TAG)
	   scsi_flags |= 0x01800000;
	   }
	 */

	/* Direction, disconnect ok, tag, CDBLen */
	writel(scsi_flags | 0x20200000 | SCpnt->cmd_len, &msg->body[0]);

	mptr = &msg->body[1];

	/* Write SCSI command into the message - always 16 byte block */
	memcpy_toio(mptr, SCpnt->cmnd, 16);
	mptr += 4;
	lenptr = mptr++;	/* Remember me - fill in when we know */

	reqlen = 12;		// SINGLE SGE

	/* Now fill in the SGList and command */
	if (SCpnt->use_sg) {
		struct scatterlist *sg;
		int sg_count;

		sg = SCpnt->request_buffer;
		len = 0;

		sg_count = dma_map_sg(dev, sg, SCpnt->use_sg,
				      SCpnt->sc_data_direction);

		if (unlikely(sg_count <= 0))
			return -ENOMEM;

		for (i = SCpnt->use_sg; i > 0; i--) {
			if (i == 1)
				sg_flags |= 0xC0000000;
			writel(sg_flags | sg_dma_len(sg), mptr++);
			writel(sg_dma_address(sg), mptr++);
			len += sg_dma_len(sg);
			sg++;
		}

		reqlen = mptr - &msg->u.head[0];
		writel(len, lenptr);
	} else {
		len = SCpnt->request_bufflen;

		writel(len, lenptr);

		if (len > 0) {
			dma_addr_t dma_addr;

			dma_addr = dma_map_single(dev, SCpnt->request_buffer,
						  SCpnt->request_bufflen,
						  SCpnt->sc_data_direction);
			if (!dma_addr)
				return -ENOMEM;

			SCpnt->SCp.ptr = (void *)(unsigned long)dma_addr;
			sg_flags |= 0xC0000000;
			writel(sg_flags | SCpnt->request_bufflen, mptr++);
			writel(dma_addr, mptr++);
		} else
			reqlen = 9;
	}

	/* Stick the headers on */
	writel(reqlen << 16 | SGL_OFFSET_10, &msg->u.head[0]);

	/* Queue the message */
	i2o_msg_post(c, m);

	osm_debug("Issued %ld\n", SCpnt->serial_number);

	return 0;
};

/**
 *	i2o_scsi_abort - abort a running command
 *	@SCpnt: command to abort
 *
 *	Ask the I2O controller to abort a command. This is an asynchrnous
 *	process and our callback handler will see the command complete with an
 *	aborted message if it succeeds.
 *
 *	Returns 0 if the command is successfully aborted or negative error code
 *	on failure.
 */
static int i2o_scsi_abort(struct scsi_cmnd *SCpnt)
{
	struct i2o_device *i2o_dev;
	struct i2o_controller *c;
	struct i2o_message __iomem *msg;
	u32 m;
	int tid;
	int status = FAILED;

	osm_warn("Aborting command block.\n");

	i2o_dev = SCpnt->device->hostdata;
	c = i2o_dev->iop;
	tid = i2o_dev->lct_data.tid;

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return SCSI_MLQUEUE_HOST_BUSY;

	writel(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_SCSI_ABORT << 24 | HOST_TID << 12 | tid,
	       &msg->u.head[1]);
	writel(i2o_cntxt_list_get_ptr(c, SCpnt), &msg->body[0]);

	if (i2o_msg_post_wait(c, m, I2O_TIMEOUT_SCSI_SCB_ABORT))
		status = SUCCESS;

	return status;
}

/**
 *	i2o_scsi_bios_param	-	Invent disk geometry
 *	@sdev: scsi device
 *	@dev: block layer device
 *	@capacity: size in sectors
 *	@ip: geometry array
 *
 *	This is anyones guess quite frankly. We use the same rules everyone
 *	else appears to and hope. It seems to work.
 */

static int i2o_scsi_bios_param(struct scsi_device *sdev,
			       struct block_device *dev, sector_t capacity,
			       int *ip)
{
	int size;

	size = capacity;
	ip[0] = 64;		/* heads                        */
	ip[1] = 32;		/* sectors                      */
	if ((ip[2] = size >> 11) > 1024) {	/* cylinders, test for big disk */
		ip[0] = 255;	/* heads                        */
		ip[1] = 63;	/* sectors                      */
		ip[2] = size / (255 * 63);	/* cylinders                    */
	}
	return 0;
}

static struct scsi_host_template i2o_scsi_host_template = {
	.proc_name = OSM_NAME,
	.name = OSM_DESCRIPTION,
	.info = i2o_scsi_info,
	.queuecommand = i2o_scsi_queuecommand,
	.eh_abort_handler = i2o_scsi_abort,
	.bios_param = i2o_scsi_bios_param,
	.can_queue = I2O_SCSI_CAN_QUEUE,
	.sg_tablesize = 8,
	.cmd_per_lun = 6,
	.use_clustering = ENABLE_CLUSTERING,
};

/**
 *	i2o_scsi_init - SCSI OSM initialization function
 *
 *	Register SCSI OSM into I2O core.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int __init i2o_scsi_init(void)
{
	int rc;

	printk(KERN_INFO OSM_DESCRIPTION " v" OSM_VERSION "\n");

	/* Register SCSI OSM into I2O core */
	rc = i2o_driver_register(&i2o_scsi_driver);
	if (rc) {
		osm_err("Could not register SCSI driver\n");
		return rc;
	}

	return 0;
};

/**
 *	i2o_scsi_exit - SCSI OSM exit function
 *
 *	Unregisters SCSI OSM from I2O core.
 */
static void __exit i2o_scsi_exit(void)
{
	/* Unregister I2O SCSI OSM from I2O core */
	i2o_driver_unregister(&i2o_scsi_driver);
};

MODULE_AUTHOR("Red Hat Software");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(OSM_DESCRIPTION);
MODULE_VERSION(OSM_VERSION);

module_init(i2o_scsi_init);
module_exit(i2o_scsi_exit);